Coal dust and air supply in siemens-martin and like furnaces



R. KRAUSS COAL DUST AND AIR SUPPLY IN SIEMENS-MARTIN AND LIKE FURNACES I Filed May 1924 Patented Feb. 2, 1926.

warren iATEhlT' OFFICE.

RICHARD KRAUSS, OF FRANKFOBT-ON-TEIE MAILFBODELEEIM, GERMANY, ASSIGNOB T0 FIRM OF FELLNER 85 ZIEGLER, AT FRAEKFGBT-OILTHE-MAIN, GERMANY.

COAL DUST AND AIR SUPPLY IN SIEMENSJBIARTIN AND LIKE FURNACES.

Application filed May 10, 1924. Serial No. 712,391.

To all whom it may concern.

Be it known that I, RICHARD KnAUss, a citizen of the German Empire, and resident of Frankfort-on-the-Main-Rodelheim, Germany, with the post-ofiice address Radilostrasse 3?, have invented certain new and useful Improvements in or Relating to Coal Dust and Air Supplies in Siemens-Martin and like Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

In the working of Siemens-Martin or like furnaces with coal dust firing, there is some difficulty in ensuring safe control of the supply of the coal dust and air. When nozzles are arranged on bot-h sides of the furnace for the supply of the coal dust, which nozzles are worked alternately, the manipulation of the necessary valves therefor demands considerable attention and the constant danger of an explosion exists.

It has previously been suggested to shut off or to reverse the burners automatically and simultaneously with the air valves during the reversing of the hot air-chambers.

In contradistinction thereto the present invention has for its object not the reversing of the air valves in relation to the hot air chambers, but an arrangement whereby an absolutely safe supply of the coal dust and of the air necessary for combustion is effected.

The members serving for controlling the supply of the coal dust and air are, according to the invention, connected by means of a positive control device in such a manner that on starting, first air is supplied for the nozzle on one side of the hearth, and then coal dust, while the opposite takes place on a reversal of the operation, the coal dust being first shut off and then the air. At the same time there is provided a. locking or safety device to prevent a wrong succession of the reversing movements.

One arrangement according to the invention is illustrated by way of example, in the accompanying drawing.

The hearth of the furnace is designated at (2. Connected to each end of the furnace is a nozzle 6 or c to which coal dust is fed, 111 known manner from a contalncr f by means of worm-conveyors d, e or the like.-

Both nozzles are also connected by means of conduits g, it through valves 2', j to a common blower 7a, or an appropriate device for delivering the necessary air for combustion. The actuating means for the conveyors d, c and the valves 2', j are connected by means of a positive control device such as a rod, an electric, hydraulic or like coupling, in such a manner that on starting one nozzle, for example 6, first its air valve i is opened and then its fuel conveyor d is rotated or brought into action. On changing over or reversal the conveyor d is first stopped and then the valve 2' closed, whilst simultaneously the air valve 7' is opened and then the conveyor e is rotated. Moreover, a locking device is provided which prevents an incorrect succession of these movements. The reversal can be effected from the operators platform bymeans of handles or switches, so that since an error is made impossible, the danger of an explosion is entirely excluded.

In order to prevent the ignition of coal particles in the conduit closed for the time being, the valve 71, or 7' (as the case may be) is preferably not entirely closed, so that a slight air current may pass continuously through the closed conduits. For this purpose there may be provided a constant small passage or lead in said valves.

I claim 1. The art of reversing open-hearth furnaces in which comminuted fuel is supplied to the air at the furnace burners which comprises effecting a stoppage of the supply of fuel at one burner and thereafter stopping the air supply thereto and simultaneously supplying air to the other burner and thereafter fuel.

2. The art of reversing open-hearth furnaces in which comminuted fuel is supplied to the air at the furnace burners which comprises efl'ecting a stoppage of the supply of fuel at one burner and thereafter stopping the air supply thereto and simultaneously supplying air to the other burner and thereafter fuel, and maintaining a scavenging flow of air after the stoppage of the air.

3. The combination with an open-hearth furnace, having means to supply air to each furnace head and means to supply pulverized fuel to such air; in combination with air valves controlling the supply of air and 4c- The combination with an open-hearth furnace having means to supply air to each furnace head and means to supply pulverized fuel to such air; in combination with air valves controlling thesupply of air and means to connect the valve operating device and the fuel supply devices to compel a reversal of the furnace in the following order, first'cut off the fuel supply and thereafter the air at one furnace head and simultaneously supply air to the other furnace head and then fuel, and means to maintain a scavenging flow of air through the air supply when in closed condition.

5. The combination with an open-hearth furnace having means to supply air to each furnace head and means to supply pulverized fuel to such air; in combination with air valves controlling the supply of air and means to connect the valve operating device and the fuel supply devices to compel a reversal of the furnace in the following order, first cut off the fuel supply and thereafter the air at one furnace head and simultaneously supply air to the other furnace head and then the fuel, and locking means to prevent a variation of the order of operation.

In testimony that I claim the foregoing as my ii'ivention I have signed my name.

RICHARD KRAUSS. 

